Brushes have been used since prehistoric times to apply pigments to a workpiece. Many types of animal hair and vegetable fiber have been used in brush manufacture. In more modern times, synthetic fibers have been used. The brush fibers are united to handles of wood, plastic or metal in several different ways. The fibers are grouped into tufts and are cemented or clamped onto the brush handle.
When such brushes are used with paints which are not thoroughly cleaned from the brush bristles after use, the brush soon becomes heavy laden with dried paint, ruining the characteristics of the brush. Since the brush bristles are permanently bonded to the handle, the brush cannot be renewed and thus must be wastefully thrown away.